Short answers, pulled from the story.
In sports, an open tournament or open competition means that anyone may enter, regardless of whether they are a professional or amateur athlete. The term can also mean the competition is open to international players, depending on the sport and the specific tournament rules.
Golf was the first sport to use the term. Prestwick Golf Club introduced the concept in 1861 when it opened its annual Challenge Belt competition to both professional and amateur golfers. That event is now known as The Open Championship or British Open.
Old Tom Morris, whose full name was Thomas Mitchell Morris, won the first open Challenge Belt competition held by Prestwick Golf Club in 1861. The best amateur finisher that year was James Ogilvie Fairlie, who placed eighth.
The Open Era of tennis began in 1968, when both amateur and professional players were permitted to compete in Grand Slam events. Before 1968, only amateur players were officially allowed to participate.
In 1986, the International Olympic Committee allowed the international federations of each sport to decide whether professional athletes could compete, effectively opening the Olympic Games to professionals. Women were first permitted to compete at the 1900 Games, when select sports such as tennis were opened to female competitors.
World Aquatics created an open category in 2023 for athletes whose gender identity differs from their birth sex, describing it as a pioneering pilot project. It was scheduled to debut at the 2023 Swimming World Cup in Berlin but was cancelled due to a lack of entries.